Thermoelectric water cooler



Nov. 14, 1961 A. c. sHEcKLl-:R

THERMOELECTRIC WATER COOLER Filed April 9, 1959 FIG. 2

INVENTOR. ADDISON C. SHECKLER A 7' TOR/VE Y 3,008,299 THERMOELECTRICWATER COOLER Addison C. Sheckler, Cato, N.Y., assignor to CarrierCorporation, Syracuse, N.Y., a corporation of Delaware Filed Apr. 9,1959, Ser. No. 805,217 Claims. (Cl. 62-3) This invention relates towater fountains of the bubbler type and, more particularly, to` a waterfountain including a thermoelectric refrigeration system permitting theutilization of same for the cooling of drinking water.

With the increase and growth of commercial and industrialestablishments, the need has arisen for providing cool water fordrinking purposes. This is generally accomplished by the use ofso-called water coolers or fountains which serve to chill the availabletap water to enhance its potabili-ty to fulfill the drinkingrequirements of the employees and patrons of these establishments. Theconventional water cooler employs a comression refrigeration system, thecooling coils of which are arranged in heat exchange relationship with awater supply source. These conventional water coolers require frequentmaintenance of the refrigeration system components; are relativelycumbersome in size, occupying valuable floor space; and are a source ofnoise resulting from the operation of the compressor motor.

The substitution of a thermoelectric refrigeration system in lieu of theaforementioned compression refrigeration system would serve tosubstantially eliminate some of the aforementioned problems, in thatmaintenance requirements, and noise resulting from relatively movingmechanical components are no longer present. However, the coolingrequirements of a water cooler have in the past been unattainable in acommercially feasible fashion, by the use of thermoelectricrefrigeration techniques. The size of the components, and the costs ofelectricity required for effecting desired temperature changes in thewater have been such as to preclude the development of an economicalapparatus.

It is with the above problems in mind that the present means have beenevolved, means permitting the utilization of a thermoelectricrefrigeration system to cool drinking water to potable temperatures,said means efficiently utilizing all of the heat pumping effects of thethermoelectric refrigeration system, whereby the size of therefrigeration system components, and the current requirements permit thedevelopment of a Water cooler having no relatively moving parts, quietin operation, and occupying a minimal volume permitting installation asa wail hung unit, desk unit or the like.

It is accordingly a primary object of this invention to provide novelmeans for placing water in heat exchange relationship with the heattransfer elements of a refrigeration system to permit effective andeicient cooling of the Water.

It is also an important object of this invention to provide an improvedwater cooler for the cooling of available tap water to a desired potabletemperature.

Another object of the invention is to provide a water cooler requiringminimal maintenance.

A further object of the invention is to provide a water cooler having nomoving parts thus eliminating noise and weer.

It is also an object of this invention to provide a compact water coolerwhich may be installed without requiring a waste of valuable commercialor industrial floor space.

An additional object of the invention is to provide novel Water coolingmeans of an extremely eiicient nature, whereby thermoelectricrefrigeration systems may be employed for cooling purposes.

It is also an object of the invention to provide a novel n 3,9%,299Patented Nov. 14, 1961 HCC method for directing water through a Watercooler to increase the effectiveness of any refrigeration systememployed in the cooling of said water. Y'

Another object of the invention is to make use of the waste water of awater cooler.

These and other objects of the invention which will become apparent inthe following disclosure and claims are achieved by provision of athermally insulated water receiving holding tank connected byappropriate supply lines to a source of potable water such as tap water.An outlet is provided on the tank for selectively discharging watertherefrom. At least one of the side walls of said tank is provided witha battery of thermoelectric couples, the cold junctions of which arearranged in heat exchange relationship with the interior of thecompartment, and the hot junctions of which are arranged in a heatexchange relationship with the exterior of the tank. A waste waterconduit is arranged in heat exchange relationship with the hotjunctions, and the flow path of the waste water is arranged incounterflow to the iiow path of the inlet water provided to the tankthrough the supply line. rPnese ow paths are directed on the oppositesides of at least one of the walls provided with the thermoelectriccouples. A thermostatically controlled valve permits the passage ofwater from the supply line over the iiow path described for the wastewater in the event that waste water is not available.

An important feature of the invention resides in the novel paths for theinlet water and cooling water which are directed in a counteriiowdirection to each other to attain a minimal temperature gradient acrossthe thermoelectric couples, thus increasing the refrigeration efflciencyof these thermoelectric couples, and permitting attainment of acommercially feasible structure employing a thermoelectric refrigerationsystem for cooling purposes.

Another feature of the invention resides in the novel arrangement of thethermostatic valve to permit inlet water to ow over the hot junctions ofthe thermoelectric couples to attain the aforementioned efficiency, inthe event that waste water is not available for dissipating heat fromthe hot junction.

An additional feature of the invention resides in the arrangement of.thermoelectric refrigeration components whereby the benefitsA of watercooling and air cooling may be employed.

The specific structural details of 4the invention, and their mode offunctioning will be made most manifest and particularly pointed out infull, clear, concise, and exact terms in conjunction with theaccompanying drawings wherein:

FIGURE 1 is a schematic cross sectional view through a water coolerconstructed in accordance with the principles of this invention; and

FIGURE 2 is a cross sectional elevational view taken on line II-II ofFIGURE 1.

Referring now more particularly to the drawings, like numerals in thevarious figures will be taken to designate like parts. j

lIn the embodiment of the invention illustrated in the drawings, thewater cooler 1li is illustrated as comprising a rectangularly shaped boxhaving an interior compartment forming a water receiving reservoir orholding tank 11. Opposite side walls 12, 12 are shown formed with abattery of thermoelectric couples 13, each couple comprising twodissimilar therrnoelectric arms labelled P and N. In accordance withconventional practice, the arm P is made up of p-type thermoelectricmaterial having a positive thermoelectric power, and the arm N is madeup of an n-type material having negative thermoelectric power. Oppositeends of the arms N and P are joined 3 by a junction 14 and the remotearm of the battery is connected to an appropriate source of directcurrent to effect current ow causing junction 14 to act as heatabsorbing cold junctions, and junctions 14 to act as heat dissipatinghot junctions. A thermally conducting electrical insulating layer 15 isprovided between the surface of wall 12 and the thermoelectric arms andtheir junctions 14 and 14 respectively. A suitable wall structure inwhich the thermoelectric couples are electrically insulated from theoutside surface of the Wall, but are in heat exchange relationshiptherewith, is more fully described in my co-pending application S.N.805,216, led April 9, 1959.

If desired fins 16 may be extended from the surface of Walls 12 and'12on either side thereof to extend the effective heat transfer area of thejunctions 14.

On the interior surface of wall 12, directed into tank 11, an inletWater baie plate 20, vertically extending parallel to wall 12. almost upto the top surface of tank 11 is provided. In the lower wall 22 of tank11, between inlet water baille plate 20'V and wall 12 -a water inletsupply line is provided connected to an appropriate water source. On theoutside of wall 12 (to the right as viewed in FIGURE l), a refrigerationsystem cooling water compartment is arranged. Cooling compartment 30shaped to provide a water trap comprises an outer wall 31 extendingparallel to wall 12 and a bottom Wall 32 extending from the bottom ofwall'12. Within compartment 30 a directing guide plate 33 extendsdownwardlyparallel to wall 31 and stopping before bottom wall 32. TheupperV part of guide plate 33 is connected to the lower part of wastewater collecting drain trough 3S, -which has a drain spout 36 leadingwaste water from trough 35 into compartment 30 on the side of guideplate 33 adjacent the outside surface of wall'12 which functions aswaste water directing means and is in heat exchange relationship withthe hot junctions 14' of the thermoelectric couples 13. At the upperpart of wall 31 on the side of .guideplate 33 opposite wall 12 adischarge connection 37 is provided for connection to an appropriatesewer or other waste. Y

Leading from the tank 11 to trough 35 via anV appropriate valved spigotor bubbler 41 for discharge of drinking water, is discharge conduit 40.y

Inlet water from the supply source may be directed to trap like coolingcompartment 30 by means of auxiliary cooling line 45. The passage ofwater through line 45 is controlled iby thermostatically actuated valve46 coupled to thermostat y47 here shown as arranged within reservoir orholding tank 11, but suitable for arrangement in a variety of otherpositions to sense a temperature condition at the hot junctions of thethermoelectricV couples which would warrant the provision of auxiliarycooling water to dissipate the heat of said junctions. Thus thethermostat 47 may be positioned in compartment 30'.

The aforedescribed, schematically illustrated water cooler, due to anincreased efficiency produced by the water iow paths provided may beformed of relatively small light weight nature thus permitting thestructure to be either wall mounted or desk mounted as desired.

Inthe described embodiment of the invention, only walls 12, 12 of thetank 11 were described as containing a battery of thermoelectriccouples, however, it will be obvious Vto those skilled in the art thatdepending on desired cooling effects, as much of the wall area of 4thetank as desired may be formed with thermoelectric couples. The wall 12has been described as having its hot junctions arranged in heat exchangerelationship with a reelectric couples employed arranged in heatexchange re- 4lationship with a water ow path, since the temperature ofthe surrounding air may in given installations provide suiicient heatdissipation.

In use, .the novel water cooler is coupled to an appropriate watersupply source and source of electrical energy for the refrigerationsystem, which in the case of the illustrated thermoelectric system mustbe a D.C. source. 'Ihe Water supply is here contemplated as having asuicient head pressure to provide for desired flow to .the bubbler 41.Thus in most industrial and commerical installations, the relativelyhigh water supply tank will provide the necessary head pressures. Wateris admitted to reservoir or water receiving holding tank 11 throughsupply line 25. In passing into holding tank 11, the water passesupwardly over the interior surface of wall 12 which results in it beingplaced in heat exchange relationship with the cold junctions 14 of thethermoelectric couples 13 therein. After passage in relatively closeYproximity to the surface of wall 12 the inlet water Hows over the topedge of bale plate 20 for storage in reservoir or tank 11.

In general use, only a portion of the Water discharged through dischargeconduit 4t? is consumed. The chilled water which would normally bewasted may here be employed for dissipating the heat at the hot junctionof the refrigerationV system thermoelectric couples. This isaccomplished by directing the waste Water through drain 36 downwardlyover the outsidev surface of Wall 12 in vheat exchange relationship withthe hot junctions 14 of the thermoelectric couples 13. At the bottom ofcompartment 30 this drain Water is upwardly directed on the oppositeside of guide plate 33 to discharge connection 37 leading to a suitablewaste, which may be either a Sewer connection or waste sump. It willthus be observed that the chilled Waste water is maintained in heatexchange relationship with the hot junctions of the thermoelectriccouples by the trap formati-011 of compartment 30.

In the event that the quantities of waste water are insufficient-toprovide adequate heat dissipation from the hot junctions as might occurWhere all of the water discharged is caught in a container, or where thewater cooler has not been used for a period of time, then the efficiencyattained by lowering of the temperature snrrounding the hot junction toproduce a minimal temperature differential between the hot and coldjunction is no longer adequate to permit utilization of a thermoelectricrefrigeration system.

In the illustrated embodiment of the invention, the hot junctions of thethermoelectric couples in wall 12 are air cooled. This may be adequateto attain desired temperature gradients across wall 172' to sufficientlycool the water in tank 11 when the cooler is not in use.

If the air cooling is not suicient or if no air cooled wall is employed,Water cooling of the hot junctions may be provided through auxiliarycooling or supply line 45. Thus, as illustrated the loss of eciency willbe indicated by a temperature rise in the water in reservoir or tank 11.This will cause thermostat 47 to open valve 46 permitting supply waterto pass through line 45 to compartment 30.

It will be apparent that the counterflow paths provided for the inletwater and the waste water over opposite sides of thermoelectric couples13 lserves to produce a minimal temperature dilferential between the hotand cold junctions of these thermoelectric couples. This is apparentwhen it is considered that the warmest inlet water, namely that rstentering holding tank 11, passes over a thermoelectric couple which isin heat exchange relationship with the warmest drain water, namely thatwhich has already owed over a major portion of the surface of wall 12.VAs the inlet water is cooled in its ow over the interior surface ofwall 12 it is in heat exchange relationship with a thermoelectric couplethe opposite junction of which is in heat exchange relationship with thecoolest waste water, namely that which has first been admitted to thedrain flue 30, so that a minimum temperature gradient across thethermoelectric couples exists.

Clearly, the aforedescribed improvements in thermo configuration can beapplied to a water cooler employing a compression refrigeration systemwith a resultant increase in efficiency. However, the water flow pathsrequired for adequate condenser cooling result in a rather elaborate andcomplex system in which the operating efficiencies are mitigated byincreased production costs.

It is thus seen that a novel water cooler has been provided in whichimproved ow paths for the inlet and drain water permit the utilizationof a thermoelectric refrigeration system for cooling purposes. Thispermits the water cooler to be made of a relatively small compact naturehaving no moving parts, not adding heat or noise to the environment.

The above disclosure has been given by way of illustration andelucidation, and not by way of limitation, and it is desired to protectall embodiments of the herein disclosed inventive concept within thescope of the appended claims,

I claim:

l. In a water fountain of the bubbler type, the combination of ahousing; a reservoir for cooled water in said housing; means coupled tosaid housing supplying water to said reservoir; bubbler means leadingfrom said reservoir permitting selective discharge of cooled watertherefrom; waste collecting means adjacent said bubbler meansl forcollecting water discharged by said bubbler means and not consumed;waste water directing means leading the waste water from said collectingmeans; means in heat exchange relationship with the supplied water, saidmeans including a thermoelectric battery having cold junctions in heatexchange relationship with the supplied water and having hot junctionsin heat exchange relationship with the water directed by said directingmeans, and a thermoelectric battery having cold junctions in heatexchange relationship with the supplied water and hot junctions in heatexchange relationship with the air; and connecting means between saidmeans for supplying water and said waste water directing means wherebysupply water may be employed to effect dissipation of heat.

2. A water fountain as in claim 1 in which a thermostatically actuatedvalve means are arranged in combination with said connecting means andsaid reservoir to permit the ow of Water through said connecting meansonly upon the occurrence of a given temperature in said reservoir.

3. In appaartus for cooling drinking water to a desired temperature toenhance its potability, said apparatus including a refrigeration systemhaving a heat absorbing element and a heat dissipating element; a waterreceiving holding tank having an inlet; a supply line coupled to theinlet of said tank and feeding water thereto from a supply source, thewater fed by said supply line being directed over a heat absorbingelement of the refrigeration system in heat exchange relationshiptherewith; a discharge conduit coupled to said tank to permit dischargeof water therefrom for consumption; a refrigeration system cooling watercompartment on said tank through which water is directed in heatexchange relationship with the heat dissipating element of therefrigeration system; an auxiliary cooling water line extending betweensaid supply line and said compartment; a thermostatically controlledvalve arranged to control the passage of water through said coolingwater line, said Valve being opened in response to an undesired rise intemperature of the water in said tank to permit the passage of supplywater to said compartment, whereby the temperature differential betweenwhich the refrigeration system must effect heat pumping is reduced thusimproving the etliciency of the system.

4. In a water fountain of the bubbler type, the combination of ahousing; a reservoir for cooled water in said housing; means coupled tosaid housing supplying water to said reservoir; bubbler means Vleadingfrom said `reservoir permitting selective discharge of cooled watertherefrom; waste collecting means adjacent said bubbler means forcollecting water discharged by said bubbler means and not consumed;thermoelectric means having a heat absorbing junction in heat exchangerelationship with the supplied water; waste water directing meansleading the waste water from said waste water collecting means into heatexchange relationship with a heat dissipating junction of saidthermoelectric means to aid in dissipating heat therefrom; connectingmeans between said means for supplying water and said waste waterdirecting means, whereby supply water may be employed to effectdissipation of heat from said thermoelectric means; and athermostatically actuated valve means arranged in combination with saidconnecting means and said reservoir to permit the ow of water throughsaid connecting means only upon the occurrence of a given temperaturedifferential in said reservoir.

5. In an apparatus for effecting a change in the temperature of water, atank adapted to contain water, inlet means associated with said tankadapted to admit water into said tank, outlet means associated with saidtank adapted to discharge water from said tank, a thermoelectric heatexchanger comprising a pair of sunfaces adapted to have differingtemperatures upon the passage of an electric current through saidthermoelectric heat exchanger, one of said Surfaces being located toeffect heat exchange with water in said tank, the other of said surfacesbeing located to effect heat exchange with a iiuid exterior of saidtank, means to collect unconsumed water discharged from said tank, meansto pass said unconsumed water in heat exchange relation with said othersurface to conserve the energy resulting in a change in thermal energythereof and means to pass additional water from a supply source thereofinto heat exchange relation with said other surface to effect additionalheat exchange therewith.

6. An apparatus as defined in claim 5 including automatic meansresponsive to the temperature of water in said tank to control the fiowof said additional water into heat exchange relation with said othersurface.

7. In a water fountain of the bubbler type, the combination of areservoir for cooled water, means to supply water to said reservoir,bubbler means leading from said reservoir permitting selective dischargeof cooled water therefrom, means to collect unconsumed waste waterdischarged from said bubbler, thermoelectric heat exchange meanscomprising a heat absorbing junction and a heat dissipating junctionspaced therefrom, said heat absorbing junction being located in heatexchange relation with water supplied to said tank, said heatdissipating junction being located in heat exchange relation with theunconsumed collected water, means to pass additional cooling fluid inheat exchange relation with said heat dissipating junctions, and meansto regulate the passage of said additional cooling fluid in heatexchange relation with said heat dissipating junctions.

`8. A water cooler comprising a water holding tank having walls; athermoelectric couple having a hot junction and a cold junction arrangedin one of the walls of said tank with the hot junction of thethermocouple in heat exchange relationship with an exterior surface ofSaid one wall and the cold junction in heat exchange relationship withan interior surface of said one wall; a cooling water compartmentarranged along the exterior surface of said one wall through which watermay flow in heat exchange relationship with the hot junction; a watersupply line coupled to said tank to feed water into said tank in heatexchange relationship with the cold junction of said couple; a dischargeline permitting the delivery of water from said tank for consumption; adrain trough in which any unconsumed water is drained to saidcompartmennwhe'reby the waste water generally present in water cooleruse may be employed to dissipate heat from the hot junction of thecouple to lower the temperature gradient thereacross and increase itseiiciency; and a thermoelectric couple arranged in another of said wallswith the het junction of said couple being air cooled.

9. A Watercooler comprising la water holding tank having walls; athermoelectric couple having a hot junction and a cold junction arrangedin one of the walls of ysaid tank with the hot junction of thethermocou-ple in heat exchange relationship with an exterior surface ofsaid one wall and the cold junction in heat exchange relationship withan interior surface of said one wall; a cooling water compartmentarranged along the exterior sur-face of said one wall through whichwater may ow in heat exchange relationship with the hot junction; awater supply line coupled to said tank to feed water into said tank inheat exchange relationship with the cold junction of Vsaidy couple; adischarge line permitting the delivery of water from said tank forconsumption; a drain trough in which any unconsu-med water is drained tosaid compartment, whereby the waste water generally present in watercooler use may be em-ployed to dissipate heat from the hot junction ofthe couple to lower the temperature gradient thereacross and increaseits etliciency; means toV direct the ilow of said unconsumed wa- Vterdrained to said compartment across the exterior surand maximumefficiency of operation of the couple.

10. In a water fountain of the bubbler type, the combination of ahousing; a reservoir for cooled Water in said housing; means coupled tosaid housing supplying water to said reservoir; bubbler means leadingfrom said reservoir permitting selective discharge of cooled watertherefrom; 4wastercollecting means adjacent said bubbler means forcollecting water discharged by said bubbler means and not consumed; athermoelectric battery comprising a therrnoelectric junction adapted tobe cooled and a thermoelectric junction adapted to be heated upon thepassage of an electric current therethrough in a predetermineddirection, said junction adapted to be cooled forming a heat absorbingjunction located in heat exchange relationship with the supplied water;waste water directing means leading the waste water from said wasteWater collecting means into heat exchange relationship with saidjunction adapted to be heated forming a heat dissipating junction, toremove heat lfrom said heat dissipating junction thereby improving theeffectiveness of said thermoelectric battery in removing heat from saidsupplied water; and lsaid thermoelectric battery including at least oneadditional junction of the type adapted to be heated upon the passagetherethrough of an electric current in said predetermined direction,said last named junction being located in heat exchange relation withambient air to utilize said ambient air for absorption and transfer ofheat from the water supplied to said reservoir.

References Cited in the file of this patent UNITED STATES PATENTS

